Influence of {101¯2} twin characteristics on detwinning in Mg-3Al-1Zn alloy

In the present work, the influence of pre-induced {101¯2} twin characteristics on detwinning activation in a basal texture magnesium alloy is systematically investigated by a combination of electron backscatter diffraction technique and mechanical tests. Samples containing pre-induced {101¯2} twin variants with different morphological characteristics are prepared by pre-strain path change tests comprised two pre-strain paths: (i) compression along the rolling direction of magnesium alloy plate; (ii) tension along the normal direction of magnesium alloy plate. In the former case, a single {101¯2} twin variant or a {101¯2} twin pair is formed in one grain. While, multiple {101¯2} twin variants are usually activated simultaneously in one grain in the latter case. During subsequent compression along normal direction, detwinning process is effectively retarded for the samples containing multiple {101¯2} twin variants in one grain. Meanwhile, the yield stress of corresponding samples is enhanced as well, compared to that of the samples containing a single {101¯2} twin variant or a {101¯2} twin pair in one grain. According to these experimental features, the possible reasons behind such phenomena are proposed and discussed.